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freebsd-skq/sys/opencrypto/ktls_ocf.c
jhb ddcef18974 Refactor driver and consumer interfaces for OCF (in-kernel crypto). 
- The linked list of cryptoini structures used in session
  initialization is replaced with a new flat structure: struct
  crypto_session_params.  This session includes a new mode to define
  how the other fields should be interpreted.  Available modes
  include:

  - COMPRESS (for compression/decompression)
  - CIPHER (for simply encryption/decryption)
  - DIGEST (computing and verifying digests)
  - AEAD (combined auth and encryption such as AES-GCM and AES-CCM)
  - ETA (combined auth and encryption using encrypt-then-authenticate)

  Additional modes could be added in the future (e.g. if we wanted to
  support TLS MtE for AES-CBC in the kernel we could add a new mode
  for that.  TLS modes might also affect how AAD is interpreted, etc.)

  The flat structure also includes the key lengths and algorithms as
  before.  However, code doesn't have to walk the linked list and
  switch on the algorithm to determine which key is the auth key vs
  encryption key.  The 'csp_auth_*' fields are always used for auth
  keys and settings and 'csp_cipher_*' for cipher.  (Compression
  algorithms are stored in csp_cipher_alg.)

- Drivers no longer register a list of supported algorithms.  This
  doesn't quite work when you factor in modes (e.g. a driver might
  support both AES-CBC and SHA2-256-HMAC separately but not combined
  for ETA).  Instead, a new 'crypto_probesession' method has been
  added to the kobj interface for symmteric crypto drivers.  This
  method returns a negative value on success (similar to how
  device_probe works) and the crypto framework uses this value to pick
  the "best" driver.  There are three constants for hardware
  (e.g. ccr), accelerated software (e.g. aesni), and plain software
  (cryptosoft) that give preference in that order.  One effect of this
  is that if you request only hardware when creating a new session,
  you will no longer get a session using accelerated software.
  Another effect is that the default setting to disallow software
  crypto via /dev/crypto now disables accelerated software.

  Once a driver is chosen, 'crypto_newsession' is invoked as before.

- Crypto operations are now solely described by the flat 'cryptop'
  structure.  The linked list of descriptors has been removed.

  A separate enum has been added to describe the type of data buffer
  in use instead of using CRYPTO_F_* flags to make it easier to add
  more types in the future if needed (e.g. wired userspace buffers for
  zero-copy).  It will also make it easier to re-introduce separate
  input and output buffers (in-kernel TLS would benefit from this).

  Try to make the flags related to IV handling less insane:

  - CRYPTO_F_IV_SEPARATE means that the IV is stored in the 'crp_iv'
    member of the operation structure.  If this flag is not set, the
    IV is stored in the data buffer at the 'crp_iv_start' offset.

  - CRYPTO_F_IV_GENERATE means that a random IV should be generated
    and stored into the data buffer.  This cannot be used with
    CRYPTO_F_IV_SEPARATE.

  If a consumer wants to deal with explicit vs implicit IVs, etc. it
  can always generate the IV however it needs and store partial IVs in
  the buffer and the full IV/nonce in crp_iv and set
  CRYPTO_F_IV_SEPARATE.

  The layout of the buffer is now described via fields in cryptop.
  crp_aad_start and crp_aad_length define the boundaries of any AAD.
  Previously with GCM and CCM you defined an auth crd with this range,
  but for ETA your auth crd had to span both the AAD and plaintext
  (and they had to be adjacent).

  crp_payload_start and crp_payload_length define the boundaries of
  the plaintext/ciphertext.  Modes that only do a single operation
  (COMPRESS, CIPHER, DIGEST) should only use this region and leave the
  AAD region empty.

  If a digest is present (or should be generated), it's starting
  location is marked by crp_digest_start.

  Instead of using the CRD_F_ENCRYPT flag to determine the direction
  of the operation, cryptop now includes an 'op' field defining the
  operation to perform.  For digests I've added a new VERIFY digest
  mode which assumes a digest is present in the input and fails the
  request with EBADMSG if it doesn't match the internally-computed
  digest.  GCM and CCM already assumed this, and the new AEAD mode
  requires this for decryption.  The new ETA mode now also requires
  this for decryption, so IPsec and GELI no longer do their own
  authentication verification.  Simple DIGEST operations can also do
  this, though there are no in-tree consumers.

  To eventually support some refcounting to close races, the session
  cookie is now passed to crypto_getop() and clients should no longer
  set crp_sesssion directly.

- Assymteric crypto operation structures should be allocated via
  crypto_getkreq() and freed via crypto_freekreq().  This permits the
  crypto layer to track open asym requests and close races with a
  driver trying to unregister while asym requests are in flight.

- crypto_copyback, crypto_copydata, crypto_apply, and
  crypto_contiguous_subsegment now accept the 'crp' object as the
  first parameter instead of individual members.  This makes it easier
  to deal with different buffer types in the future as well as
  separate input and output buffers.  It's also simpler for driver
  writers to use.

- bus_dmamap_load_crp() loads a DMA mapping for a crypto buffer.
  This understands the various types of buffers so that drivers that
  use DMA do not have to be aware of different buffer types.

- Helper routines now exist to build an auth context for HMAC IPAD
  and OPAD.  This reduces some duplicated work among drivers.

- Key buffers are now treated as const throughout the framework and in
  device drivers.  However, session key buffers provided when a session
  is created are expected to remain alive for the duration of the
  session.

- GCM and CCM sessions now only specify a cipher algorithm and a cipher
  key.  The redundant auth information is not needed or used.

- For cryptosoft, split up the code a bit such that the 'process'
  callback now invokes a function pointer in the session.  This
  function pointer is set based on the mode (in effect) though it
  simplifies a few edge cases that would otherwise be in the switch in
  'process'.

  It does split up GCM vs CCM which I think is more readable even if there
  is some duplication.

- I changed /dev/crypto to support GMAC requests using CRYPTO_AES_NIST_GMAC
  as an auth algorithm and updated cryptocheck to work with it.

- Combined cipher and auth sessions via /dev/crypto now always use ETA
  mode.  The COP_F_CIPHER_FIRST flag is now a no-op that is ignored.
  This was actually documented as being true in crypto(4) before, but
  the code had not implemented this before I added the CIPHER_FIRST
  flag.

- I have not yet updated /dev/crypto to be aware of explicit modes for
  sessions.  I will probably do that at some point in the future as well
  as teach it about IV/nonce and tag lengths for AEAD so we can support
  all of the NIST KAT tests for GCM and CCM.

- I've split up the exising crypto.9 manpage into several pages
  of which many are written from scratch.

- I have converted all drivers and consumers in the tree and verified
  that they compile, but I have not tested all of them.  I have tested
  the following drivers:

  - cryptosoft
  - aesni (AES only)
  - blake2
  - ccr

  and the following consumers:

  - cryptodev
  - IPsec
  - ktls_ocf
  - GELI (lightly)

  I have not tested the following:

  - ccp
  - aesni with sha
  - hifn
  - kgssapi_krb5
  - ubsec
  - padlock
  - safe
  - armv8_crypto (aarch64)
  - glxsb (i386)
  - sec (ppc)
  - cesa (armv7)
  - cryptocteon (mips64)
  - nlmsec (mips64)

Discussed with:	cem
Relnotes:	yes
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D23677
2020-03-27 18:25:23 +00:00

405 lines
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/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2019 Netflix Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/counter.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/ktls.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <sys/uio.h>
#include <opencrypto/cryptodev.h>
struct ocf_session {
crypto_session_t sid;
struct mtx lock;
};
struct ocf_operation {
struct ocf_session *os;
bool done;
struct iovec iov[0];
};
static MALLOC_DEFINE(M_KTLS_OCF, "ktls_ocf", "OCF KTLS");
SYSCTL_DECL(_kern_ipc_tls);
SYSCTL_DECL(_kern_ipc_tls_stats);
static SYSCTL_NODE(_kern_ipc_tls_stats, OID_AUTO, ocf,
CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
"Kernel TLS offload via OCF stats");
static counter_u64_t ocf_tls12_gcm_crypts;
SYSCTL_COUNTER_U64(_kern_ipc_tls_stats_ocf, OID_AUTO, tls12_gcm_crypts,
CTLFLAG_RD, &ocf_tls12_gcm_crypts,
"Total number of OCF TLS 1.2 GCM encryption operations");
static counter_u64_t ocf_tls13_gcm_crypts;
SYSCTL_COUNTER_U64(_kern_ipc_tls_stats_ocf, OID_AUTO, tls13_gcm_crypts,
CTLFLAG_RD, &ocf_tls13_gcm_crypts,
"Total number of OCF TLS 1.3 GCM encryption operations");
static counter_u64_t ocf_retries;
SYSCTL_COUNTER_U64(_kern_ipc_tls_stats_ocf, OID_AUTO, retries, CTLFLAG_RD,
&ocf_retries,
"Number of OCF encryption operation retries");
static int
ktls_ocf_callback(struct cryptop *crp)
{
struct ocf_operation *oo;
oo = crp->crp_opaque;
mtx_lock(&oo->os->lock);
oo->done = true;
mtx_unlock(&oo->os->lock);
wakeup(oo);
return (0);
}
static int
ktls_ocf_tls12_gcm_encrypt(struct ktls_session *tls,
const struct tls_record_layer *hdr, uint8_t *trailer, struct iovec *iniov,
struct iovec *outiov, int iovcnt, uint64_t seqno,
uint8_t record_type __unused)
{
struct uio uio;
struct tls_aead_data ad;
struct cryptop *crp;
struct ocf_session *os;
struct ocf_operation *oo;
struct iovec *iov;
int i, error;
uint16_t tls_comp_len;
os = tls->cipher;
oo = malloc(sizeof(*oo) + (iovcnt + 2) * sizeof(*iov), M_KTLS_OCF,
M_WAITOK | M_ZERO);
oo->os = os;
iov = oo->iov;
crp = crypto_getreq(os->sid, M_WAITOK);
/* Setup the IV. */
memcpy(crp->crp_iv, tls->params.iv, TLS_AEAD_GCM_LEN);
memcpy(crp->crp_iv + TLS_AEAD_GCM_LEN, hdr + 1, sizeof(uint64_t));
/* Setup the AAD. */
tls_comp_len = ntohs(hdr->tls_length) -
(AES_GMAC_HASH_LEN + sizeof(uint64_t));
ad.seq = htobe64(seqno);
ad.type = hdr->tls_type;
ad.tls_vmajor = hdr->tls_vmajor;
ad.tls_vminor = hdr->tls_vminor;
ad.tls_length = htons(tls_comp_len);
iov[0].iov_base = &ad;
iov[0].iov_len = sizeof(ad);
uio.uio_resid = sizeof(ad);
/*
* OCF always does encryption in place, so copy the data if
* needed. Ugh.
*/
for (i = 0; i < iovcnt; i++) {
iov[i + 1] = outiov[i];
if (iniov[i].iov_base != outiov[i].iov_base)
memcpy(outiov[i].iov_base, iniov[i].iov_base,
outiov[i].iov_len);
uio.uio_resid += outiov[i].iov_len;
}
iov[iovcnt + 1].iov_base = trailer;
iov[iovcnt + 1].iov_len = AES_GMAC_HASH_LEN;
uio.uio_resid += AES_GMAC_HASH_LEN;
uio.uio_iov = iov;
uio.uio_iovcnt = iovcnt + 2;
uio.uio_offset = 0;
uio.uio_segflg = UIO_SYSSPACE;
uio.uio_td = curthread;
crp->crp_op = CRYPTO_OP_ENCRYPT | CRYPTO_OP_COMPUTE_DIGEST;
crp->crp_flags = CRYPTO_F_CBIMM | CRYPTO_F_IV_SEPARATE;
crp->crp_buf_type = CRYPTO_BUF_UIO;
crp->crp_uio = &uio;
crp->crp_ilen = uio.uio_resid;
crp->crp_opaque = oo;
crp->crp_callback = ktls_ocf_callback;
crp->crp_aad_start = 0;
crp->crp_aad_length = sizeof(ad);
crp->crp_payload_start = sizeof(ad);
crp->crp_payload_length = crp->crp_ilen -
(sizeof(ad) + AES_GMAC_HASH_LEN);
crp->crp_digest_start = crp->crp_ilen - AES_GMAC_HASH_LEN;
counter_u64_add(ocf_tls12_gcm_crypts, 1);
for (;;) {
error = crypto_dispatch(crp);
if (error)
break;
mtx_lock(&os->lock);
while (!oo->done)
mtx_sleep(oo, &os->lock, 0, "ocfktls", 0);
mtx_unlock(&os->lock);
if (crp->crp_etype != EAGAIN) {
error = crp->crp_etype;
break;
}
crp->crp_etype = 0;
crp->crp_flags &= ~CRYPTO_F_DONE;
oo->done = false;
counter_u64_add(ocf_retries, 1);
}
crypto_freereq(crp);
free(oo, M_KTLS_OCF);
return (error);
}
static int
ktls_ocf_tls13_gcm_encrypt(struct ktls_session *tls,
const struct tls_record_layer *hdr, uint8_t *trailer, struct iovec *iniov,
struct iovec *outiov, int iovcnt, uint64_t seqno, uint8_t record_type)
{
struct uio uio;
struct tls_aead_data_13 ad;
char nonce[12];
struct cryptop *crp;
struct ocf_session *os;
struct ocf_operation *oo;
struct iovec *iov;
int i, error;
os = tls->cipher;
oo = malloc(sizeof(*oo) + (iovcnt + 2) * sizeof(*iov), M_KTLS_OCF,
M_WAITOK | M_ZERO);
oo->os = os;
iov = oo->iov;
crp = crypto_getreq(os->sid, M_WAITOK);
/* Setup the nonce. */
memcpy(nonce, tls->params.iv, tls->params.iv_len);
*(uint64_t *)(nonce + 4) ^= htobe64(seqno);
/* Setup the AAD. */
ad.type = hdr->tls_type;
ad.tls_vmajor = hdr->tls_vmajor;
ad.tls_vminor = hdr->tls_vminor;
ad.tls_length = hdr->tls_length;
iov[0].iov_base = &ad;
iov[0].iov_len = sizeof(ad);
uio.uio_resid = sizeof(ad);
/*
* OCF always does encryption in place, so copy the data if
* needed. Ugh.
*/
for (i = 0; i < iovcnt; i++) {
iov[i + 1] = outiov[i];
if (iniov[i].iov_base != outiov[i].iov_base)
memcpy(outiov[i].iov_base, iniov[i].iov_base,
outiov[i].iov_len);
uio.uio_resid += outiov[i].iov_len;
}
trailer[0] = record_type;
iov[iovcnt + 1].iov_base = trailer;
iov[iovcnt + 1].iov_len = AES_GMAC_HASH_LEN + 1;
uio.uio_resid += AES_GMAC_HASH_LEN + 1;
uio.uio_iov = iov;
uio.uio_iovcnt = iovcnt + 2;
uio.uio_offset = 0;
uio.uio_segflg = UIO_SYSSPACE;
uio.uio_td = curthread;
crp->crp_op = CRYPTO_OP_ENCRYPT | CRYPTO_OP_COMPUTE_DIGEST;
crp->crp_flags = CRYPTO_F_CBIMM | CRYPTO_F_IV_SEPARATE;
crp->crp_buf_type = CRYPTO_BUF_UIO;
crp->crp_uio = &uio;
crp->crp_ilen = uio.uio_resid;
crp->crp_opaque = oo;
crp->crp_callback = ktls_ocf_callback;
crp->crp_aad_start = 0;
crp->crp_aad_length = sizeof(ad);
crp->crp_payload_start = sizeof(ad);
crp->crp_payload_length = crp->crp_ilen -
(sizeof(ad) + AES_GMAC_HASH_LEN);
crp->crp_digest_start = crp->crp_ilen - AES_GMAC_HASH_LEN;
memcpy(crp->crp_iv, nonce, sizeof(nonce));
counter_u64_add(ocf_tls13_gcm_crypts, 1);
for (;;) {
error = crypto_dispatch(crp);
if (error)
break;
mtx_lock(&os->lock);
while (!oo->done)
mtx_sleep(oo, &os->lock, 0, "ocfktls", 0);
mtx_unlock(&os->lock);
if (crp->crp_etype != EAGAIN) {
error = crp->crp_etype;
break;
}
crp->crp_etype = 0;
crp->crp_flags &= ~CRYPTO_F_DONE;
oo->done = false;
counter_u64_add(ocf_retries, 1);
}
crypto_freereq(crp);
free(oo, M_KTLS_OCF);
return (error);
}
static void
ktls_ocf_free(struct ktls_session *tls)
{
struct ocf_session *os;
os = tls->cipher;
crypto_freesession(os->sid);
mtx_destroy(&os->lock);
explicit_bzero(os, sizeof(*os));
free(os, M_KTLS_OCF);
}
static int
ktls_ocf_try(struct socket *so, struct ktls_session *tls)
{
struct crypto_session_params csp;
struct ocf_session *os;
int error;
memset(&csp, 0, sizeof(csp));
switch (tls->params.cipher_algorithm) {
case CRYPTO_AES_NIST_GCM_16:
switch (tls->params.cipher_key_len) {
case 128 / 8:
case 256 / 8:
break;
default:
return (EINVAL);
}
csp.csp_mode = CSP_MODE_AEAD;
csp.csp_cipher_alg = CRYPTO_AES_NIST_GCM_16;
csp.csp_cipher_key = tls->params.cipher_key;
csp.csp_cipher_klen = tls->params.cipher_key_len;
csp.csp_ivlen = AES_GCM_IV_LEN;
break;
default:
return (EPROTONOSUPPORT);
}
/* Only TLS 1.2 and 1.3 are supported. */
if (tls->params.tls_vmajor != TLS_MAJOR_VER_ONE ||
tls->params.tls_vminor < TLS_MINOR_VER_TWO ||
tls->params.tls_vminor > TLS_MINOR_VER_THREE)
return (EPROTONOSUPPORT);
os = malloc(sizeof(*os), M_KTLS_OCF, M_NOWAIT | M_ZERO);
if (os == NULL)
return (ENOMEM);
error = crypto_newsession(&os->sid, &csp,
CRYPTO_FLAG_HARDWARE | CRYPTO_FLAG_SOFTWARE);
if (error) {
free(os, M_KTLS_OCF);
return (error);
}
mtx_init(&os->lock, "ktls_ocf", NULL, MTX_DEF);
tls->cipher = os;
if (tls->params.tls_vminor == TLS_MINOR_VER_THREE)
tls->sw_encrypt = ktls_ocf_tls13_gcm_encrypt;
else
tls->sw_encrypt = ktls_ocf_tls12_gcm_encrypt;
tls->free = ktls_ocf_free;
return (0);
}
struct ktls_crypto_backend ocf_backend = {
.name = "OCF",
.prio = 5,
.api_version = KTLS_API_VERSION,
.try = ktls_ocf_try,
};
static int
ktls_ocf_modevent(module_t mod, int what, void *arg)
{
int error;
switch (what) {
case MOD_LOAD:
ocf_tls12_gcm_crypts = counter_u64_alloc(M_WAITOK);
ocf_tls13_gcm_crypts = counter_u64_alloc(M_WAITOK);
ocf_retries = counter_u64_alloc(M_WAITOK);
return (ktls_crypto_backend_register(&ocf_backend));
case MOD_UNLOAD:
error = ktls_crypto_backend_deregister(&ocf_backend);
if (error)
return (error);
counter_u64_free(ocf_tls12_gcm_crypts);
counter_u64_free(ocf_tls13_gcm_crypts);
counter_u64_free(ocf_retries);
return (0);
default:
return (EOPNOTSUPP);
}
}
static moduledata_t ktls_ocf_moduledata = {
"ktls_ocf",
ktls_ocf_modevent,
NULL
};
DECLARE_MODULE(ktls_ocf, ktls_ocf_moduledata, SI_SUB_PROTO_END, SI_ORDER_ANY);
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